An international team of archaeologists has excavated and examined 8,000-year-old projectile points (spear- and arrowheads) at two sites in Yemen and Oman. They’ve found that ancient Arabians independently invented a process to create distinctive projectile points — called fluting — that was first used by Native Americans about 5,000 years earlier. Various types of fluted points and preforms from Manayzah, Yemen: (1) double-fluted preform...